Chemical Oxygen Demand reduction in industrial wastewater using locally isolated bacteria

Abstract

Wastewater that has been discharged from the pineapple industry contributes to high levels of Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD) and Suspended Solids (SS). The high levels of COD concentrations in wastewater are toxic to biological life and will affect aquatic environment. Currently, there are many methods that have been developed to treat pineapple industry wastewater such as ozonation, reverse osmosis and filtration. However, these conventional methods are costly and generate large amounts of sludge. Biological treatment may be a good alternative since its operational cost is less and it creates an environmental friendly atmosphere compared to the conventional methods. In this study, the effectiveness of COD reduction involving a single bacterial culture D, G and I isolated from a pineapple industry wastewater were used in batch system. The COD reduction of pineapple industry wastewater was carried out using bacterial culture and pellet. The performance of these systems in reducing the COD level was monitored within 3 days. The COD reduction was analyzed using a Hach DR/4000 U spectrophotometer. The bacterial pellet D, G and I showed a maximal COD reduction of 87%, 77% and 94% respectively after 3 days exposure to wastewater. The wastewater treatment using bacterial pellet showed higher COD reduction as compared to treatment using whole bacterial culture. FESEM analysis showed that bacteria D, G and I appeared as rod shaped.